Sterilizer for container covers



June 6, 1967 G. A. GUCKEL STERILIZER FOR CONTAINER Filed April 19, 1965 COVERS 7 Sheets-Sheet 1 F G-I INVENTOR.

GiiH/VET 4. 600m;

June 6, 1967 G. A. GUCKEL STEHILIZER FOR CONTAINER COVERS 7 Sheets-Sheet 2 Filed April 19, 1965 II M.

I NVE N TOR GEE/M21- 4. Gus/(EL June 6, 1967 G. A. GUCKEL 3,323,856

STERILIZER FOR CONTAINER COVERS Filed April 19, 1965 '7 Sheets-Sheet 4 BY M I W M84 4.

FIG-5 June 6, 1967 G. A. GUCKEL 3,323,856

STERILIZER FOR CONTAINER COVERS Filed April 19, 1965 7 Sheets-Sheet 5 FIG-8 INVENTOR. GEEHAer/Q Gum 4 M [Sid/(a1 June 6, 1967 Filed April 19, 1965 G. A. GUCKEL STERILIZER FOR CONTAINER COVERS '7 Sheets-Sheet 6 INVENTOR. GEe/werfl. Gum/:1.

June 6, 1967 e. A. GUCKEL 3,323,356

STERILIZER FOR CONTAINER COVERS Filed April 19, 1965 7 sheets-Sheet 7 FIG-9 INVENTOR. 65/2/1421- 4, Gum 1.

M ABA/4,;

irrae/via Patented June 6, 1967 3,323,856 STERILIZER FGR CONTAINER CQVERS Ger-hart A. Guckel, Los Altos, Califl, assignor to James Dole Engineering Co., San Francisco, Caliii, a corporation of Nevada Fiied Apr. 19, 1965, Ser. No. 449,029 9 Claims. (Cl. 2178) This invention relates to the sterilization of container covers and, more particularly, to an improved sterilizer for container covers and the like. The improved sterilizer of this invention is especially useful in a sterile or aseptic packaging process in which containers and their covers are sterilized, the sterile containers filled with a sterile product, and the filled containers then covered and sealed-all such operations being conducted under sterile or aseptic conditions.

As explained in Patent No. 2,771,644, entitled, Apparatus for sterilizing Container Covers, in an aseptic packaging process (which process usually involves rigid containers such as open-mouth metal cans and is generally referred to as canning), steam or other gas is heated to an appropriate sterilizing temperature in excess of 212 F. and is then introduced into the packaging or canning apparatus to maintain sterile conditions therein. Such apparatus need not be significantly pressurized, whereupon the sterile gaseous environment therein can approach atmospheric pressure, because the sterile gas introduced into the apparatus is itself eifective to prevent the ingress of outside or ambient air and other gases thereinto as a result of its permitted continuous escape (which is small because of the relatively low pressures) through any openings in the apparatus. The details of an aseptic canning process of the type being considered are set forth, for example, in Patents No. 2,771,645 and No. 2,685,520.

As is well known, sterilization by heat is a function of time and temperature, and the relationship therebetween is generally logarithmic with temperature being dominate so that the time factor can be materially reduced as the temperature is elevated. Evidently, in commercial operations it is practicably necessary to have a high rate of production and the attainment of this objective is apparently facilitated in an aseptic canning process by elevating the temperature of the sterilizing gas since this should have the elfect of reducing the time required to produce complete sterilization of the containers and covers therefor.

However, there are applicable temperature limitations due primarily to the characteristics of the containers employed (usually Open-mouth metal cans) WhlCh are comprised of materials that are sensitive to and deteriorate when heated to temperatures in the general order and in excess of 450 F. For example, in the canning of food products, it is essential for product preservation that a hermetic seal be provided about the compartment in which the food product is contained. To facilitate this result, the seams and joints of the containers are usually equipped with a gasket material that is damaged by such temperatures. Also, it has been found that certain coating materials with which metal cans are covered (and the tin solder used for sealing the body seams thereof) are similarly affected adversely by such high temperatures.

The seemingly incompatible factors of limitation on temperature and reduced residence time of the containers and their covers in the atmosphere of the sterilizing gas can be made compatible in a cover sterilizer if the sterilizing gas can be impinged directly against those portions of the cover (namely, the edges thereof) which are most susceptible to bacterial contamination and if turbulence can be created along the boundary layer of the cover at such locations thereon to materially increase the rate of heat transfer thereto. Accordingly, an object, among others, of the present invention is to provide an improved sterilizer for container covers in which this result is attained.

Summarizing such improved sterilizer, it comprises an enclosure having an entrance open to atmosphere through which covers are introduced thereinto and an exit through which sterile covers are discharged for subsequent placement onto product-filled containers. Each cover is transported from the entrance to the exit of the enclosure by rotatable screw conveyors that support a succession of covers in a columnar orientation; and included Within the enclosure is a gas distributing means for directing a sterilizing gas into the spaces between the threads of such conveyor for impingement against the edges of the covers supported therebysuch covers being rotated by the conveyor so that substantially each incremental portion of the cover edge is subjected to the direct impingement of the sterilizing gas, and the turbulence enforced upon the gas by the rotational displacements of the conveyor and covers resulting in a rapid transfer of heat to the container covers.

An embodiment of the invention is illustrated in the accompanying drawings in which:

FIGURE 1 is a diagrammatic top plan view of an aseptic food packaging or canning system embodying the invention;

FIGURE 2 is an enlarged, broken top plan view of the cover sterilizer comprised in such system;

FIGURE 3 is a broken, vertical sectional view taken along the line 33 of FIGURE 2;

FIGURE 4 is a broken, transverse sectional view taken along the line 44 of FIGURE 3;

FIGURE 5 is a broken, side view in elevation of the cover sterilizer, the view being taken generally along the plane 55 of FIGURE 4;

FIGURE 6 is an enlarged, broken, vertical sectional view taken along the line 6-6 of FIGURE 2;

FIGURE 7 is a transverse sectional view taken along the line 77 of FIGURE 3;

FIGURE 8 is a transverse sectional view taken along the line 88 of FIGURE '7;

FIGURE 9 is a fragmentary enlargement of a portion of the apparatus illustrated in FIGURE 8; and

FIGURE 10 is a diagrammatic view illustrating the principles of the invention. The apparatus illustrated diagrammatically in FIGURE 1 constitutes an aspetic packaging or canning system in which containers (particularly open-mouth metal cans) are sterilized, are then filled with a sterile product, and are thereafter closed with a sterile cover so that each container defines a hermetic enclosure about the sterile product therein. Such apparatus includes a container sterilizer 15 having an infeed section 16 whereat empty containers are fed onto a conveyor for movement into and through the sterilizer 15. Sterilized containers are discharged from the sterilizer 15 through a housing 17 and into a filler 18 at which a sterile product (a food product, for example, such as milk) is introduced into the containers. A by-pass section 19 is arranged with the housing 17 and filler 18 so as to return to the infeed section 16 any excess containers or containers otherwise not admitted into the filler 18.

The filled containers are transported from the filler 18 through a sterile atmosphere defined by a covered conveyor 20 to closure apparatus 21 such as a can seamer. As each container is admitted into the closure apparatus 21, a sterile cover or lid is discharged in synchronism therewith from a cover sterilizer 22, each filled container and a cover therefor are then united in the closure apparatus 21 to hermetically seal the sterile product Within the container, and the filled containers are then discharged through a conveyor section 23.

The entire apparatus including the container sterilizer 15, the cover sterilizer 22, the housing 17 and conveyor 20, the filler 18, and the closure apparatus 21 has a sterile atmosphere maintained throughout. In order to maintain such sterile atmosphere, a gaseous fluid such as steam, superheated to a temperature of about 500 F. at approximately atmospheric pressure, is continuously directed into the apparatus at appropriate locations. In the system illustrated, a heater unit 24 which, for example, may be of the gas burner type as indicated by the burner mechanism 25, has water delivered thereto through an infeed conduit 26. The water is converted into superheated steam within the heater 24 and is delivered to such locations along the apparatus by means of a discharge conduit 27.

In the apparatus shown, the sterile atmosphere within the filler 18 is provided by sterilizing air pumped through the heater 24 by a suitable blower or fan and conveyed to the filler by a manifold 28 (which is broken off in FIG- URE 1 for purposes of simplifying the drawing and to permit a clear illustration of components of the system otherwise concealed by the manifold). With respect to the present invention, the container sterilizer 15, filler 18, closure apparatus 21, heater unit 24, and the respectively associated and intervening components all may be completely conventional.

The cover sterilizer 22 comprises an enclosure in the form of a housing 29 having upwardly extending insulated walls 30, a bottom wall or closure plate 31, and a top plate or cover 32. The polygonal configuration of the housing 29 in cross-section is shown most clearly in FIGURE 7, and it is also most evident in this FIGURE that movable doors 33 and 34 are hingedly arranged with certain of the upwardly extending walls 30 to provide access to the interior of the housing, which interior is denoted in general with the numeral 35. The closure doors 33 and 34 (or other wall components) may comprise transparent panels 36 and 37 so that the interior 35 can be observed without opening the doors. Conventional clasps 38 and 39 may be respectively associated with the doors 33and 34 for releasably securing the same in the closed position thereof, and although it is not necessary to define a fluid tight seal about the doors, peripherally oriented gasket members 40 and 41 may be respectively associated therewith to minimize the escape of sterilized gas thereabout.

Located within the enclosure 35 are a plurality of conveyor units which, for identification, are respectively denoted in their entirely as 42a, 42b, 43a and 43b. As shown most clearly in FIGURE 7, the conveyors are radially oriented with respect to a center defined by an upwardly extending manifold 44 which, adjacent the upper end thereof, is connected to the conduit 27 through which sterilized gas is discharged from the heating unit 24. The conveyors 43a and 43b are diametrically oriented with respect to such center, and the conveyors 42a and 42b are interposed therebetween and are respectively spaced therefrom and from each other by equal angular distances. In the structure illustrated, the conveyors 42a and 42b are spaced from the respectively adjacent conveyors 43a and 43b by approximately 60 and are similarly separated from each other by about 60.

The conveyors 42 and 43 are all substantially identical and respectively function to transport covers downwardly through the enclosure 35 from the entrance ends of the conveyors to the exit ends thereof. Accordingly, only one of the conveyor units will be described in specific detail, and it will be understood that such description applies equally to the others. Thus, referring to FIGURE 3 in particular, it is seen that the conveyor 42a comprises a pair of helical worms or dropping screws 45 and 46 which may be referred to as inner and outer screws since the screw 45 is located inwardly of the screw 46 with respect to the distributing manifold 44. The centers of the screws 45 and 46 define a line which is radially oriented with respect to the center established by the distribution manifold 44; and the radial spacing between the screws along such line is sufliciently great that covers 47 can be fed downwardly by such screws with the marginal edge portions of each cover riding in the threads of the screws. Accordingly, a plurality of successive covers 47 can be fed downwardly in spaced-apart relation by the screws the spacing between adjacent covers being substantially equal to the thickness of the threads (i.e., the center to center spacing of adjacent threads).

The conveyor 42a also includes (see FIGURE 7) a pair of guides 48 and 49 in the form of vertically oriented rods that are substantially parallel to the longitudinal axes of the dropping screws 45 and 46. The rods 48 and 49 are diametrically oriented and are adapted to substantially abut the covers 47 so as to prevent lateral displacements thereof as they are transported downwardly through the enclosure by the screws 45 and 46. The rods can be supported in any suitable manner and, for example, may extend through openings provided therefor in the cover 32 and seat at their lower ends within aligned recesses provided in the base plate 31.

Associated with the conveyor 42a is a magazine 50 located above the cover 32 and adapted to receive a stack 51 of juxtaposed covers 47 therein. In the structure illustrated, the magazine 50 is seen to comprise a plurality of rods (there being four in the structure shown respectively denoted 52, 53, 54 and 55) that are disposed to define a generally annular space adapted to receive a stack 51 of covers therewithin and to support the covers in columnar orientation. The rods defining the magazine 50 are secured to the cover 32 by anysuitable means as, for example, by screwing the same into threaded openings provided therefor in the cover, and extend upwardly therefrom. Quite evidently, the annular space defined by the rods 52 through 55 must bealigned with an opening through which covers 47 can be advanced in succession by the dropping screws 45 and 46. Such opening is denoted in FIGURE 2 with the numeral 56, and constitutes the entrance of the conveyor 42a.

The opening 56, although generally conforming to and approximating in dimension the diameter of the annular covers 47, has diametral extensions or merges at diametrically opposite areas with substantially circular openings 57 and 58 that respectively receive the dropping screws 45 and 46 therein. Accordingly, each cover 47 can move downwardly through the magazine 50 and into engagement with the threads of the dropping screws 45 and 46, which then advance each cover through the entrance defined by the opening 56 and downwardly through the enclosure 35 toward exit of the conveyor 42a.

The weight of a stack 51 of covers 47 supported in columnar arrangement by the guides 52 through 55 above the top wall 32 is ordinarily sufficiently great to bias each successive lowermost cover of the stack into engagement with the threads of the dropping screws 45 and 46. It might be noted, however, that toward the end of a run (at which time only a few covers 47 may be disposed within the magazine 50), it may be desirable to place a Weight upon such remaining few covers to positively urge the same downwardly and thereby overcome any pressure force developed within the enclosure 35 as a consequence of the sterilized gas admitted thereto and which might tend to prevent such covers from engaging the threads of the dropping screws. The columnar orientation of the covers is maintained Within the enclosure 35 because of the cooperative disposition of the dropping screws 45 and 46 and the guide rods 48 and 49.

The inner and outer dropping screws 45 and 46 extend upwardly from the bottom plate 31 and, quite apparently, the screws must be rotatably supported. For this purpose, the screws at their upper ends are respectively journalled in bearing structures generally denoted 59 and 50. As shown most clearly in FIGURE 3, the bearing structure 59 comprises a bearing block or journal 61 having a plurality (three in the structure shown) of depending legs or spacers 62 that are adapted to seat upon the upper surface of the cover 32 and thereby locate the joui'nal a spaced distance thereabove. The journal 61 is fixedly related to the cover 32 by a plurality of elongated cap screws 63 that extend downwardly through the spacers 62 and are threadedly received within tapped openings provided therefor in the cover. A closure plate 64 extends over the journal and is clamped thereto by the cap screws 63.

The journal 61 has an opening 65 therein that rotatably receive as cylindrical bearing 66 forming an extension of the dropping screw 45 and which may be threadedly mounted thereon. The precise vertical location of the bearing 66 is fixedly determined by one or more lock nuts 67. Through the described arrangement, the dropping screw 45 adjacent the upper end thereof is maintained in a substantially vertical disposition by the bearing structure 59, and is also rotatably supported thereby because of the cooperative arrangement of the bearing 66 within the journal opening 65 therefor. The construction of the bearing structure 60 is the same as that of the bearing structure 59 and will not, therefore, be described in detail-4t being understood that the explicit description of the bearing structure 59 applies equally thereto.

The exit of the conveyor 42a is defined by an annular exit Opening 68 provided by the base plate 31 in alignment with the entrance opening 56 provided by the cover 32. The base plate 31 is also provided with a pair of diametral openings 69 and 70 that merge with the exit opening 68 and respectively receive therein the dropping screws 45 and 46the threads of which terminate adjacent the exit opening 68 in a relatively sharp or increased pitch that rapidly releases each successive lowermost cover 47 and permits the same to drop through the exit opening 68 and onto a track defined by inner and outer rails 71 and 72. The rails 71 and 72 are in the form of recesses or channels provided by inner and outer track members 73 and 74 which are disposed along the underside of the base plate 31 and are bolted or otherwise rigidly secured thereto (by means not shown). The track defined by the rails 71 and 72 is dimensioned to receive each cover thereon and support the same during displacement thereof out of the cover sterilizer 22 for use in the closure apparatus 21.

In this respect, and as indicated most clearly in FIG- URES 2 and 4, the track is arcuate and extends in a counter-clockwise direction from (i.e., angularly clockwise with respect thereto) the conveyor 43b to a location beyond the conveyor 43a whereat it merges with and into an arcuate track defined by a pair of rails 75 and 76 that form extensions of the aforementioned rails 71 and 72. The rails 75 and 76 are respectively provided by trackmembers 77 and 78 that form a part of a transfer mechanism generally denoted 79 which is functionally interposed between the cover sterilizer 22 and the closure apparatus 21 but actually forms a part of such closure apparatus.

In this connection, and as indicated in FIGURES 1 and 2, containers 80, after being sterilized and filled with a sterile product in the filler apparatus 18, are advanced into the closure apparatus 21 whereat they are positively engaged by a star wheel 81 or similar displacement member, the operation of which is timed with the advancement of sterilized covers into the closure apparatus by the transfer mechanism 79. The time relationship is such that each cover is able to meet a container, and after being appropriately positioned thereon is sealingly related thereto. As stated hereinbefore, the closure apparatus and function thereof may be completely conventional and the transfer mechanism 79 ordinarily forms a component thereof.

In the cover sterilizer 22, each cover 47 is advanced along the track by a pusher finger that engages the cover along a trailing edge portion thereof and applies a pushing force thereto which causes the cover to be slidably displaced along the track in a counter-clockwise direction, as

6 viewed in FIGURES 1 and 2. The rails 71 and 72 are sufficiently low that a cover supported thereupon slides freely beneath the base plate 31. However, the pusher finger must extend slightly above the cover so as to positively engage the same; and to afford sufficient clearance for the pusher finger, the base plate 31 is provided with an arcuate, downwardly facing channel or recess 82 intermediate the rails 71 and 72. In the particular structure illustrated, and referring specifically to FIGURES 3, 4 and 5, it will be seen that there are six such pusher fingers each of which is denoted with the numeral 83--the suffixes a through 1 being added thereto for purposes of differentiation.

The fingers 83 are spaced from each other by equal angular distances, and are carried by and project upwardly from a cylindrical carrier or cup 84 fixedly secured to a central hub 85 through a plurality of radially disposed spokes 86 (there being six in number, respectively denoted 86a through 86]). The hub 85 is afiixed to a stub shaft 87 by any suitable means, such as keys 88, so as to rotate therewith, and the shaft is equipped above the hub 85 with a gear 89 that is rotatably driven through a drive gear 90 and gear train associated therewith which will be described subsequently. Also fixedly secured to the shaft 87 below the hub 85 is a relatively large-diameter gear 91 which is keyed or otherwise fixedly secured to the shaft so as to rotate therewith. The shaft immediately below the gear 91 seats in a recess provided therefor in a bearing plate 92, and the shaft is appropriately jonrnalled in such plate on bearings 93 so as to be freely rotatable with res ect thereto.

The gear 89 is an intermediate drive gear that meshes with the aforementioned drive gear 90 and with a gear 94 keyed or otherwise fixedly secured to a downwardly projecting extension 95 of the inner dropping screw 45. The extension 95 projects downwardly through the inner track member 73 and is equipped thereat with bearings which define a rotatable relationship therewith. The extension 95 at the lower end thereof is received within a retaining plate 96 secured to the track member 73 in spaced relation therewith by cap screws and spacers (not shown), and a thrust washer (as illustrated) is interposed between the retaining plate 96 and gear 94. Quite evidently, rotation of the drive gear 90 will cause the driven gear 94 to rotate because of its connection therewith through the intermediate gear 89 and, as a consequence, the inner dropping screw 45 will be rotated.

At the same time, the outer dropping screw 46 will be synchronously rotated because of its connection with the gear 91 through the driven gear 97 which is keyed to a collar 98 afiixed to a downwardly projecting extension 99 of the dropping screw 46. The extension 99 at its lower end is reduced somewhat in diameter and projects into a boss provided therefor in the bearing plate 92, which is equipped thereat with a bearing 100 to facilitate rotational movement of the dropping screw. Since the gear 91 is mounted upon the shaft 87 as is the gear 89, it is evident that both of the dropping screws 45 and 46 will be rotated whenever the gear 89 is rotated by the drive gear 90.

The drive gear 90 is keyed to a shaft 101 that extends downwardly through the base plate 31 and track member 73, and at it lower end is received within an opening provided therefor in a retainer plate 102 secured to the track member in spaced relation therewith by cap screws and spacers, as in the manner of the retainer plate 96. A thrust washer may be interposed between the retainer plate 102 and the drive gear 90, and a hearing may be used in association with the track member 73 to provide a suitable journal support for the shaft 191 therein. Located above the base plate 31 is a bearing structure 103 that includes a journal bearing 104 rotatably supporting the shaft 101, and a thrust bearing 105 therefor.

Circumjacent the shaft 101 in juxtaposition with the thrust bearing 105 is the central hub portion of a lower 7 timing flange 106 which hub has mounted thereon a gear 107 that is keyed thereto so as to rotate therewith. Secured to the lower timing flange by a plurality of cap screws 108 is an upper timing flange 109 keyed to the shaft 101 so as to rotate therewith. With the described arrangement, whenever the gear 107 is driven, it enforces rotation upon the lower timing flange 106 which, in turn, positively rotates the upper timing flange 109 because of the positive connection defined therebetween by the cap screws 108. The shaft 101 is driven by the upper timing flange 109 because it is keyed thereto; and, accordingly, the aforementioned drive gear 90 is rotated as are the dropping screws 45 and 46. The cap screws S extend through elongated openings in one or the other of the timing flanges 106 or 109 so that slight angular adjustments may be made in the relative locations of these two components for purposes of timing the apparatus.

The gear 107 is driven by a gear 110 in mesh there with which is keyed to a shaft 111 extending upwardly through a pivot bracket 112. The gear 110 is disposed belowthe pivot bracket 112, and a set collar 113 is secured to the shaft below the gear 110 to limit upward movement of the shaft. Thrust washers may be interposed between the gear 110 and the set collar 113 and pivot bracket 112. Located above the pivot bracket 112 is a clutch mechanism that includes the upper end portion 114 of the shaft 111-which end portion is of somewhat reduced diameter and has a spring seat or retaining collar 115 fixedly secured thereto by any suitable means such as a set screw. Bearing upwardly against the seat 115 is a helical compression spring 116 that at its lower end seats upon a throw-out element 117 selectively displaceable axially with respect to the shaft 111 and upper end portion thereof, but is splined or keyed thereto so as to prevent relative rotation therebetween.

As shown most clearly in FIGURE 6, the lower flange 118 of the throw-out element has an offset or step in the downwardly facing lower surface thereof, generally indicated at 119, having an angular length of approximately 180. This offset is adapted to mate with a complementary offset in the upwardly facing upper surface of a clutch plate 120 freely rotatable with respect to the shaft 111 except for the connection defined therebetween via the throw-out element 117. The clutch plate 120 is disposed above and in facing juxtaposition with the drive plate 121 drivingly connected with the clutch plate 120' through a shear pin 122 that extends therethrough and may be a common 4d nail. The shear pin 122 may extend loosely into an opening provided therefor in a gear 123 that is keyed to the drive plate so as to positively rotate the same.

The gear 123 is in mesh with a drive gear 124 keyed or otherwise secured to an input drive shaft 125 so as to be rotated thereby. The input shaft 125 comprises a part of the closure apparatus 21 and the gear 124 is simply mounted thereon at an appropriate location. The axial position of the gear along the shaft is determined in one direction by a sleeve 126 which is affixed to the shaft by a set screw, and in the opposite direction by a thrust washer 127 which is located above the pivot bracket 112. The shaft at its lower end is journalled in a base 128 that also comprises a part of the container closing apparatus 21.

The pivot bracket 112 is supported upon the input shaft 125 for angular displacements with respect thereto, and the shaft is rotatable relative to the pivot bracket which is provided wit-h a horizontally disposed flange 129 adjacent the lower edge thereof that extends along the base plate 31 in spaced relation therewith. This flange in conjunction with a cap screw 130 which is received within a tapped opening provided therefor in a boss 131 with which the base plate 31 is equipped, is adapted to fixedly anchor the pivot bracket in any position of angular adjustment thereof within the limits defined by an elongated slot 132 (FIGURE 2) formed in such flange 129. The purpose of this arrangement is to enable the cover sterilizer 22 and particularly the gearing thereof to be adjusted with respect to the closing apparatus 21 so as to be driven thereby.

As seen best in FIGURE 6, the pivot bracket 112 also has a leg 133 extending angularly therefrom that at its outer end has a bracket 134 fixedly secured thereto, as by means of cap screws 135. At its upper end the bracket 134 extends inwardly and is provided adjacent the inner end thereof with a pivot pin 136 extending there- ;through which pivotally supports a throw-out arm 137 extending along one face of such upper end portion of the bracket. At its extreme inner end, the throw-out arm 137 is equipped with a yoke 138 that straddles the throw-out element 117, and the yoke is provided along each arm thereof with an inwardly projecting pin 139 that engages the throw-out element while permitting rotation thereof. Adjacent its upper outer end, the bracket 134 has a knob or crank element 140 rotatably mounted thereon along an axis that is substantially aligned in a horizontal sense with the pivot axis of the pin 136 although spaced outwardly therefrom. The crank 140 is provided with a crank pin 141 located within an elongated slot 142 formed in the throw-out arm 137.

With this arrangement, the throw-out element 117 can be disengaged from the clutch plate 120 by rotating the crank 140 thonigh in a clockwise direction, as viewed in FIGURE 6, which, because of the cooperative engagement of the crank pin 141 in the slot 142, will cause the throw-out arm 137 to be angularly displaced in a clockwise direction about the pivot pin 136. Such angular displacement of the throw-out. arm 137 is sufficiently great to elevate the throw-out element 117 above the clutch plate so that the mating offsets 119 of the throw-out element and clutch are disengaged. Suchdisengagement of the throw-out element and clutch will permit the shaft 111 to be rotated independently of the gear 123, drive gear 124 and input shaft 125, as by means of a crank-like handle 143 which is adapted to be removably positioned upon the upper end portion 114 of the shaft 111.

The mechanism is in the nature of a one-revolution clutch in that if the throw-out element 117 is elevated to effect its disengagement with the clutch plate 120 and if the shaft 111 is then rotated slightly, the crank can be released whereupon the compression spring 116 attempts to re-establish driving engagement between the throw-out element and clutch plate. However, such driv ing engagement is prevented until the throw-out element 117 and shaft 111 have been rotated through approximately 360, or one revolution, to again bring the mating abutments 119 into alignment, at which time the spring 116 can bias the element 117 downwardly to re-establish the driving engagement.

As shown in FIGURES 3, 4 and 5, the cover sterilizer 22 is supported upon a. platform 144 that is secured to the frame structure of the closing apparatus 21, as by means of bolts 145. The .platform is stabilized with respect to the closing apparatus by adjustable studs or supports 146 that are vertically oriented and are located generally at the mergence of the platform with the closing apparatus. Additionally, one or more angularly disposed, adjustable struts 147 extend between the platform 144 and closing apparatus, and in addition to providing supplementary support for the platform, permit angular adjustments of the platform to effect proper angular alignment of the cover sterilizer 22 with the closing apparatus 21.

' The bearing plate 92 is removably supported upon the platform 144 by a plurality of fasteners 148 which may take the form shown in FIGURE 5. In this event, each fastener has a threaded shank 149 that extends upwardly through the horizontally disposed base 150 of the platform and seats against the undersurface of the bearing plate 92. The threaded shank 149 at its upper end is reduced in diameter, as shown at 151, and extends upwardly through the bearing plate 92 and is fixedly 9. secured .thereto by means of a nut 152 which threadedly engages such restricted end portion 151. Evidently, the vertical position of the bearing plate 92 with respect to the base 150 of the platform 144 is determined by appropriately rotating the shank 149 which threadedly engages the opening provided therefor in the base 150. Any position of adjustment of the shank is maintained by tightening a lock-nut 153 provided for this purpose.

The described arrangement for removably mounting the bearing plate 92 upon the platform 144 permits hearing plates to be readily interchanged, should this be desired, for the purpose of altering the gear train to change the speedof operation of the cover sterilizer or to change :the location of the screws45 and 46 which is necessary when the size or diameter of the covers being accommodated thereby is varied. The spacing between the dropping screws 45 and 46 would have to be changed to either reduce the spacing therebetween in the case of covers of smaller diameter, or to increase the spacing therebetween for covers of larger diameter.

It will be noted that the base plate 31 is removably supported upon the bearing plate 92 by a plurality of fastener elements (FIGURE generally designated with the numeral 154, each of which comprises a spacer interposed between the base plate and bearing plate and a pair of cap screws respectively arranged with such plates to secure the same to the spacer. Also, .the space or gear compartment which is located below the base plate 31 and above the platform 144 has side walls or closure components 155 mounted thereabout since sterilizing fluid within the compartment 35 can escape downwardly therefrom and into the gear compartment through the exit opening 68 associated with the conveyor 42a and through which each succeeding lowermost cover 47 transported thereby is dropped onto the track defined by the inner and outer rails 71 and 72.

As described hereinbefore, the four screw conveyors, 42a, 42b, 43a and 43b, are oriented along equally spaced radii of a semi-circle, the origin of which is efiectively defined by the longitudinal axis of the distributor conduit 44. This conduit extends downwardly into the chamber 35 through an opening provided therefor in the cover 32 of the sterilizer and may be fixedly located in any suitable manner, as by means of an annulus or washer 156 welded or otherwise fixedly related to the conduit and secured to the cover 32 by cap screws 157. The conduit at its upper end is connected to a source of s'terlized fluid, such as superheated steam, as shown in FIGURE 1, and such fluid is discharged from the conduit adjacent the lower end thereof.

Oriented about the conduit 44 in outwardly spaced relation therewith are a plurality of baflles-there being five in number in the specific illustration shown in FIG- URE 7, which bafiles are respectively denoted 158a, 153b, 1580, 159a and All of the baflles extend substantially from the bottom plate 31 .to the cover 32 and taking the bafie 158b, for example, it is seen that at its lower end it has a mounting block 160!) secured thereto by a cap screw 16111 and that the mounting block is fastened to the bottom plate 31 by a plurality of cap screws 1621;. At its upper end, referring to FIGURE 8,

the baflie 15812 is similarly secured to a mounting block 16312, as by means of a cap screw, and the mounting block, in .turn, is fastened to the cover 32 by one or more cap screws 16%.

All of the handles 158 are substantially identical and are essentially rectangular members of planar configuration that terminate adjacent the upwardly extending longitudinal edges thereof in substantial juxtaposition with the respectively associated inner dropping screws. The disposition of each baflie with respect to the associated dropping screws is one of generally tangential relation. Thus, as shown in FIGURE 7 the baflle 158a terminates adjacent and in substantially tangential relation with the inner dropping screws 45 of the two conveyors 42a and 43a; the battle 1585 is similarly disposed with respect to the inner screws 45 of the conveyors 42b and 43b; and the baffle 1580 has the same orientation and disposition relative to the inner dropping screws 45 of the conveyors 42a and 42b.

The two bafiles 159a and 15% are substantially identical and are functionally similar to the baflies 158. Thus, each of the bafiles 15? is secured at its lower end to the bottom plate 31 and at its upper end to the cover 32. These bafiles are angularly turned adjacent the outer longitudinal edge portions thereof, as shown at a and 16512, so as to snugly engage the rear wall of the sterilizer, and at their inner ends these baffies terminate in substantial abutment with the respectively adjacent inner droppin screws 45 of the conveyors 43a and 43b. The baiiies 159, rather than being substantially tangent to the respectively associated inner dropping screws, are cordially disposed with respect thereto and approach a condition in which they are very nearly radially disposed with respect to such dropping screws. Thus, the baffles 159 more efiectively prevent the escape of sterilizing fluid therepast than the bafiles 158 which, as will be described in greater detail hereinafter, are intended to direct the escape or egress of sterilizing fluid therepast in a particular manner.

All of the baflies 158 and 159 in conjunction with the inner dropping screws 45 of the conveyors 42 and 43 form a plenum chamber generally denoted in FIGURE 7 With the numeral 166. The plenum chamber 166 is filled with sterilizing fluid that discharges the'reinto from the conduit 44, and such fluid is directed outwardly from the chamber, principally by the baffles 158, into the enclosure 35 of which the plenum chamber forms a part. More particularly, and referring especially to FIGURES 9 and 10the latter of wln'ch is essentially diagrammatic and indicates the applicability of the invention to a singleconveyor cover sterilizer, it is seen that each of the container covers 47 has a marginal edge portion received within the threads of the dropping screws 45 and 46, which threads are respectively denoted 167 and 168. Since the threads 167 and 168 are continuous from the top wall 32 to the bottom plate 31, each cover 47 is maintained within these threads as it is transported or dropped from the entrance of the conveyor to the exit thereof. Throughout this displacement of the cover 47, the frictional engagement of the rotating dropping screws therewith effects substantially uninterrupted rotation of the cover as it is dropped toward the exit end of the conveyor. Accordingly, and with respect to FIGURE 10 in particular, each incremental edge portion of the cover 47 will be angularly displaced through the thread 167 one or more times during the period that the cover is transported from the entrance end to the exit end of the conveyor (in a typical installation, this period which is the residence time of each cover 47 within the enclosure 35 approximates 1 /2 minutes).

Throughout this entire period, sterilizing fluid is directed by the bafiles associated with each inner dropping screw 45 (the baffles 158!) and 158s in the illustration of FIGURE 10) through the thread 167 thereof for impingement against the edge portion of each cover disposed along the length of the dropping screws. Since each cover is continuously rotated, substantially each incremental edge portion thereof has sterilizing fluid impinged directly thereagainst during trwsit of the cover through the enclosure 35. This is especially significant because it is the edge portion of each cover, particularly in the case of the cover being for a metal can, which is highly susceptible to bacterial contamination. Thus, the very areas most likely to be contaminated are directly subjected to the sterilizing eifects of the superheated steam or other sterilized gas.

Further, it has been found that the rotational motion of each inner dropping screw 45 and the rotational motion of each cover 47 engaged thereby cooperate in association with the adjacent bafiles 158 to cause considerable turbulence of the sterilizing fluid moving through the thread 167. Such turbulence materially improves the heat exchange relationship of the sterilizing fluid with each cover 47 so as to elevate quickly the temperature of each cover to the requisite sterilizing temperature and thereafter maintain such temperature to assure a complete sterilization of each cover during a minimum residence time in Which the cover is transported from the entrance end of the conveyor to the exit end thereof.

The disposition of each bafile 158 in which it terminates adjacent an inner dropping screw and in substantial tangential relation therewith is effective to guide the fluid into and through the thread 167 of the adjacent dropping screw, and the relatively sharp corner portion of the bafile thereat not only permits it to be brought into close proximity with the outer face of each thread so as to minimize the escape of fluid therepast, but is also causes an edge effect that contributes to the turbulent'flow of the fluid through the thread 167. The baffies 159 operate in somewhat the same manner although because of the disposition thereof, it is primarily intended that they minimize the escape of fluid at the locations thereof.

As indicated hereinbefore, all of the screw conveyors 42 and 43 are substantially identical both in structure and function and operate to process concurrently a plurality (four in the structure shown) of stacks 51 of container covers 47. Thus, the capacity of the cover sterilizer 22 is four times as great as a similar sterilizer having only one screw conveyor. Further, all of the conveyors operate at the same time whenever the input shaft 125 is rotated. Such rotation of the input shaft causes rotation of the gear 123, the shaft 111 (through the shear pin 122 and clutch components 114 through 121, inclusive), the gear 110, gear 109, shaft 101, gear 90 and finally the gear 89. As shown in FIGURE 4, the gear 89 is in mesh with the gear 94 of the conveyor 42a as heretofore described, and thereby causes rotation of the inner dropping screw 45 thereof. In an identical manner, the gear 89 is in meshing engagement with the corresponding gear 94 of each of the other conveyors; and for purposes of identification in FIGURE 4, such corresponding gears are respectively denoted 94a, 94b and 940, and the shafts respectively associated therewith are designed 95a, 95b and 95c. Thus, the inner dropping screw 45 of each conveyor is rotated whenever the input shaft 125 is angularly displaced.

Similarly, the outer dropping screw 46 of the conveyor 42a is rotated along with the inner dropping screw thereof because of the driving engagement of the gear 91, which is mounted upon'the shaft 87 and is therefore rotated along with the shaft and gear 89, with the gear 97 which is mounted upon the projection 99 of the outer dropping screw 46 of the conveyor 42a, as heretofore described. Each of the conveyors is similarly equipped with a gear 97; and for purposes of differentiation in FIGURE 4, such corresponding gears are respectively designated 97a, 97b and 970, and the shaft extensions respectively corresponding thereto are denoted 99a, 99b and 990. Thus, all of the outer dropping screws 46 are rotated concurrently and in enforced synchronism with the inner dropping screws.

All of the conveyors 42 and 43 function concurrently to accept each successive lowermost cover 47 from the associated stack 51 thereof and advance such covers from the entrances defined by the openings 56 of the various conveyors to the exists defined by the opening 68 thereof. Since the conveyors operate concurrently and in synchronous relation, they can be and are timed to drop at essentially the same time through the exists thereof and onto the track defined by the rails 71 and 72 the four covers 47 that comprise at any particular moment the lowermost covers then being transported by the conveyors.

The carrier 84 rotates continuously, and as shown in FIGURE 4, is equipped with six pusher fingers 83, fou

of which are in position at any time just prior to the covers being dropped to respectively engage the next four covers 47 dropped concurrently through the respective exit openings 68 of the conveyors 42 and 43 and advance such covers toward the discharge end of the track and onto the rails 75 and 76 which form the track of the transfer mechanism 79. The covers are then advanced along such track of the transfer mechanism by pusher fingers 169 rotated by the input shaft 125, which fingers displace the covers into the closure apparatus 21 per se of which the transfer mechanism forms a part.

The rate of operation of the sterilizer is such that four covers 47 are dropped concurrently by the conveyors (that is, one cover per conveyor), such covers are respectively engaged along a trailing marginal edge portion thereof by the respectively adjacent pusher fingers 83 and are advanced thereby into the transfer mechanism 79, and then the next four successive covers (one per conveyor) are dropped onto the track defined by the inner and outer rails 71 and 72 and the process is repeated. The provision of six rather than four pusher fingers equally spaced about the carrier 84 permits such element to rotate at a lower velocity than would be the case if there were only four such fingers oriented and disposed for respective engagement with the four covers dropped concurrently by the four conveyors. More specifically, the element 84 need only rotate through slightly more than 180 in order to clear the track of four covers 47- dropped thereonto and to have four pusher fingers 83 approaching a position for engagement with the next four covers dropped by the conveyors 42 and 43 (the actual rotation in the structure shown from pick-up position to pick-up position will approximate 240). Thus, the element 84 need only rotate in slight excess of about one-half the angular velocity which would otherwise be required if there were only four pusher fingers respectively oriented for concurrent engagement with four covers dropped synchronously by the conveyors 42 and 43.

The pivot bracket 112 enables the gear train of the cover sterilizer 22 to be properly engaged with the drive gear 124 which is carried by the input shaft and is therefore fixedly located in accordance with the structural character of the closing apparatus 21. The clutch mechanism permits the cover sterilizer to be selectively disengaged from such drive gear 124 and rotated by hand through one or more cycles, should this be desired; and the shear pin 122 is a safety factor which automatically brings about disengagement of the cover sterilizer from the drive gear 124 (or more specifically, the gear 123 driven thereby) should a jam or other malfunction occur within the sterilizer unit.

While in the foregoing specification an embodiment of the invention has been illustrated and described in considerable detail for purposes of making a complete disclosure thereof, it will be apparent to those skilled in the art that numerous changes may be made in such details without departing from the spirit and principles of the invention.

What is claimed is:

1. Apparatus for sterilizing container covers, comprising an enclosure having an entrance for the admission of covers thereinto and an exit for their discharge and from which the covers are advanced to a closing apparatus for application to sterile containers having a sterile product therein, gas admission means for introducing a sterilizing gas into said enclosure, conveying means for transporting the covers between said entrance and exit and including a plurality of cooperable and substantially parallel rotatable screws spaced apart to receive and support a succession of said covers in spaced apart columnar orientation and for rotating the covers essentially in the respective planes thereof as they are thus supported and positively advanced by the screws toward said exit, means for rotating said screws to so advance said covers, and gas dist buting means for directing such sterilizing gas into the spaces between the successive covers and against the edges thereof as they are rotated, said ga distributing means including a pair of battle plates extending in an axial direction relative to said screWs and having spaced apart edges closely adjacent the threads of one of said screws in the vicinity where said one screw contacts the moving covers, said edges being respectively disposed on the opposite sides of the area of said contact and defining with said one screw gas emitting apertures of the spaces between said threads thereof for directing such sterilizing gas against the edges of the covers supported thereby.

2. Apparatus for sterilizing container covers, comprising an enclosure having an entrance for the admission of covers thereinto and an exit for their discharge and from which the covers are advanced to a closing apparatus for application to sterile containers having a sterile product therein, conveying means for transporting the covers between said entrance and exit and including a plurality of cooperable and substantially parallel rotatable screws spaced apart to receive and support a succession of said covers in spaced apart columnar orientation and for rotating the covers essentially in the respective plane thereof as they are thus supported and positively advanced by the screws toward said exit, means for rotating said screws to so advance said covers, gas distributing means for directing a sterilizing gas into the spaces between the successive covers and against the edges thereof as they are rotated, said gas distributing means including mean defining a chamber within said enclosure and comprised at least in part of a pair of baffle plates extending in an axial direction relative to said screws and having spaced apart edges closely adjacent the threads of one of said screws in the vicinity where said one screw contacts the moving covers, said edges being respectively disposed on opposite sides of the area of said contact and defining with said one screw gas emitting apertures of the spaces between said threads thereof for directing such sterilizing gas against the edges of the covers supported thereby, and said gas distributing means including also a gas admission inlet communicating with said chamber for introducing a sterilizing gas thereinto.

3. The apparatus of claim 2 in which one of said bafiie plates is angularly disposed with respect to the aforesaid one screw and is generally tangentially oriented relative thereto.

4. The apparatus of claim 2 in which said one of said screws defines with one other of said screws a pair of rotatable screws spaced apart by a distance substantially equal to the diameter of said container covers so as to receive the same therebetween, and said apparatus further comprising guide structure cooperatively arranged with said pair of screws so as to prevent lateral displacements of said covers and maintain with said screws the columnar orientation of the covers, said guide structure and the other of said pair of screws being located exteriorly of said chamber.

5. Apparatus for sterilizing container covers, comprising an enclosure having a plurality of spaced apart entrances for the respective admission of covers thereinto and a plurality of exits respectively aligned with said entrances for the discharge of covers and from which the covers are advanced to a closing apparatus for application to sterile containers having a sterile product therein, gas admission means for introducing a sterilizing gas into said enclosure, a plurality of conveying means respectively arranged with said entrances and their associated exists for transporting covers therebetween, each of said conveying means including a plurality of cooperable and substantially parallel rotatable screws spaced apart to receive and support a succession of said covers in spaced apart columnar orientation and for rotating the covers essentially in the respective planes thereof as they are thus supported and positively advanced by the screws toward the associated exit, means for rotating said screws to so advance said covers, and gas distributing means for directing such sterilizing gas into the spaces between the successive covers of each column thereof and against their edges as they are rotated, said gas distributing means including a pair of battle plates extending in an axial direction relative to said screws and having spaced apart edges closely adjacent the threads of one of said screws in the vicinity where said one screw contacts the moving covers, said edges being respectively disposed on the opposite sides of the area of said contact and defining with said one screw gas emitting apertures of the spaces between said threads thereof for directing such sterilizing ga against the edges of the covers supported thereby.

6. The apparatus of claim 5 in which said baflie plates together with the screws respectively associated therewith define a chamber within said enclosure, and in which said gas admission mean communicates with said chamber for admitting sterilizing gas thereinto.

7 The apparatus of claim 6 in which certain of said bafile plates are angularly disposed with respect to their associated screws and are substantially tangentially oriented with respect thereto.

8. Apparatus for sterilizing container covers, comprising an enclosure having an entrance for the admission of covers thereinto and an exit for their discharge and from which the covers are advanced to a closing apparatus for application to sterile containers having a sterile product therein, gas admission means for introducing a sterilizing gas into said enclosure, conveying means for transporting the covers between said entrance and exit and including a rotatable screw having a substantially continuous helical thread extending between said entrance and exit to receive the marginal edge portions of a succession of said covers in spaced apart columnar orientation which covers are characterized by rotating essentially in the respective planes thereof as they are positively transported toward said exit means for rotating said screw to so transport said covers, and gas distributing means for directing such sterilized gas into the spaces between the successive covers and against the edges thereof, said ga distributing means including a pair of baffie plates extending in an axial direction relative to said screws and having spaced apart edges closely adjacent the threads of one of said screws in the vicinity where said one screw contacts the moving covers, said edges being respectively disposed on the opposite sides of the area of said contact and defining with said one screw gas emitting apertures of the spaces between said threads thereof for directing such sterilizing gas against the edges of the covers supported thereby, the sterilizing gas directed into the spaces between the covers and against the edges thereof passing through said thread and the movement of the thread and movements of the covers relative to said bafiie creating turbulence in such gas effective to facilitate head transfer therefrom to said covers.

9. The apparatus of claim 8 in which the edge portions of said baffle plates adjacent said screw has relatively sharp corners extending therealong to further implement the creation of turbulence in said gas.

References Cited UNITED STATES PATENTS 2,771,644 11/1956 Martin 21-78 2,875,564 3/1959 Werge et a1.

MORRIS O. WOLK, Primary Examiner.

I. ZATARGA, Assistant Examiner, 

1. APPARATUS FOR STERILIZING CONTAINER COVERS, COMPRISING AN ENCLOSURE HAVING AN ENTRACE FOR THE ADMISSION OF COVERS THEREINTO AND AN EXIT FOR THEIR DISCHARGE AND FROM WHICH THE COVERS ARE ADVANCED TO A CLOSING APPARATUS FOR APPLICATION TO STERILE CONTAINERS HAVING A STERILE PRODUCT THEREIN, GAS ADMISSION MEANS FOR INTRODUCING A STERILIZING GAS INTO SAID ENCLOSURE, CONVEYING MEANS FOR TRANSPORTING THE COVERS BETWEEN ENTRANCE AND EXIT AND INCLUDING 